Mercurial > hg > CbC > CbC_gcc
diff gcc/config/i386/crtfastmath.c @ 0:a06113de4d67
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author | kent <kent@cr.ie.u-ryukyu.ac.jp> |
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date | Fri, 17 Jul 2009 14:47:48 +0900 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/gcc/config/i386/crtfastmath.c Fri Jul 17 14:47:48 2009 +0900 @@ -0,0 +1,89 @@ +/* + * Copyright (C) 2005, 2007, 2009 Free Software Foundation, Inc. + * + * This file is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 3, or (at your option) any + * later version. + * + * This file is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * Under Section 7 of GPL version 3, you are granted additional + * permissions described in the GCC Runtime Library Exception, version + * 3.1, as published by the Free Software Foundation. + * + * You should have received a copy of the GNU General Public License and + * a copy of the GCC Runtime Library Exception along with this program; + * see the files COPYING3 and COPYING.RUNTIME respectively. If not, see + * <http://www.gnu.org/licenses/>. + */ + +#define MXCSR_DAZ (1 << 6) /* Enable denormals are zero mode */ +#define MXCSR_FTZ (1 << 15) /* Enable flush to zero mode */ + +#ifndef __x86_64__ +/* All 64-bit targets have SSE and DAZ; + only check them explicitly for 32-bit ones. */ +#include "cpuid.h" +#endif + +static void __attribute__((constructor)) +#ifndef __x86_64__ +/* The i386 ABI only requires 4-byte stack alignment, so this is necessary + to make sure the fxsave struct gets correct alignment. + See PR27537 and PR28621. */ +__attribute__ ((force_align_arg_pointer)) +#endif +set_fast_math (void) +{ +#ifndef __x86_64__ + unsigned int eax, ebx, ecx, edx; + + if (!__get_cpuid (1, &eax, &ebx, &ecx, &edx)) + return; + + if (edx & bit_SSE) + { + unsigned int mxcsr = __builtin_ia32_stmxcsr (); + + mxcsr |= MXCSR_FTZ; + + if (edx & bit_FXSAVE) + { + /* Check if DAZ is available. */ + struct + { + unsigned short int cwd; + unsigned short int swd; + unsigned short int twd; + unsigned short int fop; + long int fip; + long int fcs; + long int foo; + long int fos; + long int mxcsr; + long int mxcsr_mask; + long int st_space[32]; + long int xmm_space[32]; + long int padding[56]; + } __attribute__ ((aligned (16))) fxsave; + + __builtin_memset (&fxsave, 0, sizeof (fxsave)); + + asm volatile ("fxsave %0" : "=m" (fxsave) : "m" (fxsave)); + + if (fxsave.mxcsr_mask & MXCSR_DAZ) + mxcsr |= MXCSR_DAZ; + } + + __builtin_ia32_ldmxcsr (mxcsr); + } +#else + unsigned int mxcsr = __builtin_ia32_stmxcsr (); + mxcsr |= MXCSR_DAZ | MXCSR_FTZ; + __builtin_ia32_ldmxcsr (mxcsr); +#endif +}